The invention relates to endoscopic instruments having a rotatably mounted and detachable coupling part.
Endoscopic instruments as are for example applied in resectoscopy, generally comprise a shank through which operating instruments typically in the form of a working insert are led, and these are connected to the shank at the proximal side. With these instruments and via suitable connections, a rinsing liquid is introduced into the shank, led to the region of operation and subsequently suctioned away again together with the tissue remains.
Generally, with such endoscopic instruments one differentiates between those with a continuous rinsing from those instruments with an intermittent rinsing.
The shanks of the instruments with a continuous rinsing are designed with double walls and are termed “continuous flow” shanks. With these shanks, rinsing fluid is continuously supplied to the operation region via an inner shank tube, whilst rinsing fluid is simultaneously suctioned away again via an annular gap formed by the inner and outer shank tube. It is known to design endoscopic instruments with a “continuous flow” shank such that a working insert led in the inner shank tube may be rotated together with the inner shank tube, whilst the outer shank tube is not rotated. This is advantageous, since a rotation of the outer shank could traumatize the tissue which surrounds it. However in contrast, there exits the disadvantage that the outer diameter of “continuous flow” shanks is very large which is intrinsic of their design, and that the body tissue which surrounds the shank is burdened in a different manner.
Endoscopic instruments with an intermittent rinsing with which an equally large sling is applied for removing tissue as with the continuous flow shanks do not have this disadvantage. Such instruments have a simple hollow shank, so that the outer diameter may be designed significantly smaller than with “continuous flow” shanks. However the disadvantage with these shanks is again that the working insert may only be rotated together with the shank.
Known endoscopic instruments with an intermittent rinsing attempt to avoid this disadvantage, in which the working insert in combination with the hollow shank may be rotated and the conduit connections with the flexible tubings connected thereto remain stationary on rotation of the working insert. However by way of this, a traumatization of the tissue, for example a urethra is not reduced as is desired.